Well it's time to start the Bella Court Cinema and a new house. This is my first build, so I am going to need some guidance. We will break ground around the 16th of April. And yes I will be stealing I mean borrowing some ideals.

+1 regarding the sound proofing. Spray foam is not a good choice for sound isolation either. The spray foam people will probably tell you it's the best thing to ever happen to sound isolation, but from what I've read it doesn't perform well at lower frequencies.

Also, have you considered enlisting one of the acoustic design services? A barrel ceiling will probably introduce some "issues" that will need to be dealt with. My guess is it will tend to focus the sound into the center of the room.

Don't overlook the need for a significant upgrade in the HVAC for this room,

Air tight soundproofed room, 9 people, small space heater (Projector), equipment and lights. Without an over-sized set up it will get ugly, even in the winter. If the duct work is connected to the rest of the house you need to take special measures to minimize sound traveling through the ducts. One solution is to use acoustically lined ducts.

Don't overlook the need for a significant upgrade in the HVAC for this room,

Air tight soundproofed room, 9 people, small space heater (Projector), equipment and lights. Without an over-sized set up it will get ugly, even in the winter. If the duct work is connected to the rest of the house you need to take special measures to minimize sound traveling through the ducts. One solution is to use acoustically lined ducts.